The invention refers to a thermo-electric safety igniter with a reignition lock on a gas valve combination for a gas heating furnace or similar for safely preventing reignition following switching-off before the safety igniter is again ready for operation.
Safety igniters of this type are known. Their layout with reignition locks is recommended for safety reasons or if necessary, imperatively prescribed. An example of such an arrangement is described in DD-PS 1 24 835 where its mode of operation is shown generally valid in schematic form (FIGS. 7 to 13). Generally with the known reignition locks, a so-called cam is attached to both the main valve head and the safety igniter valve head. Both cams have claw-shaped bevel-edges which together form a break-away coupling. The break-away coupling cannot be released; when withdrawing the operating rod in the open direction of the main valve, the pilot gas valve is closed whereby of course a foreseen detent coupling is released between the safety igniter valve head and the valve rod of the safety igniter magnets. The valve rod remains in its position until complete de-energization of the safety igniter magnets because the anchor is held fast further by the magnet yoke. If the magnet is de-energized, the valve rod is pushed under the influence of a compression spring until the detent coupling is re-established.
With this solution it is disadvantageous that complicatedly shaped individual components are necessary for its realization and that further the cams form a relatively rigid connection with each other, a relatively rigid control in their respective axial direction and a fixed connection with their respective valve heads. Due to the layout of the various components of the housing, there is the danger that the valve heads are no longer parallel to the valve seats and the valves cannot close tightly or a very high manufacturing accuracy is necessary which is not desired for mass-production. Further it is disadvantageous that this solution is not suitable in connection with a rotary slide as main valve for the main gas flow and pilot gas flow.
The given invention in the patent claim takes as a basis the problem of developing a thermo-electric safety igniter with a reignition lock on a gas valve combination which is suitable for using a rotary slide as main valve for the main gas flow and the pilot gas flow. Thereby it should have the simplest possible layout and should be suitable for use in mass-production.
According to the invention, the problem is solved by the named characteristics in the marked part of the patent claim.